Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Widely distributed throughout central and eastern North America, from southern Ontario and Quebec in Canada, south to North Carolina and west to Colorado and the edge of the Mississippi River basin.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous
Danger Level
Harmless; they pose no medical threat to humans, though they are known to be quite defensive and may bite repeatedly or musk if handled.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Red List: Least Concern. Populations are stable, though they face threats from habitat loss and persecution by humans who mistake them for venomous Cottonmouths.
Physical Description
Heavy-bodied snake with keeled scales. Coloration ranges from brown, gray, to reddish-brown with darker crossbands or blotches that are widest on the back and thinner on the sides. Head is relatively flat and wider than the neck; eyes have round pupils. The underside is typically cream or yellowish with reddish-brown half-moon crescents.
Size & Dimensions
Adults typically range from 61 to 107 cm (24 to 42 inches). The specimen in the image appears to be an adult or sub-adult based on the robust head shape and scale definition.
Habitat
Highly aquatic; commonly found in lakes, ponds, marshes, rivers, and streams. They prefer areas with basking sites such as logs or rocks and plenty of vegetation at elevations from sea level up to 1,500 meters.
Behavior & Temperament
Diurnal and crepuscular, though they may forage at night during hot weather. Extremely defensive; when threatened, they flatten their bodies to appear larger and will strike and bite or release a foul-smelling musk and feces to deter predators.
Diet & Feeding
Primarily piscivorous, consuming various fish and amphibians (frogs, toads, and tadpoles). They use an active foraging strategy, searching underwater or along the shoreline for prey which they swallow alive without constriction.
Reproduction
Viviparous (gives birth to live young) rather than laying eggs. Mating occurs in spring, and females give birth to 15-30 young between August and October.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus). Distinct differences include the Cottonmouth's vertical pupils, heat-sensing pits, and thick white facial stripe, whereas the Watersnake has round pupils and dark vertical labial scales on the 'lips'.
Conservation Status
IUCN Red List: Least Concern. Populations are stable, though they face threats from habitat loss and persecution by humans who mistake them for venomous Cottonmouths.
Cultural Significance
Often misunderstood and killed due to fear of venomous snakes. Ecologically, they are vital for controlling fish and amphibian populations and serve as a food source for larger predators like herons and birds of prey.
Notable Features
Excellent swimmers that can remain submerged for substantial periods. Their dark vertical bars on the labial (lip) scales are a key diagnostic feature for the genus Nerodia.